STOP MILKING MONEY OUT OF ME

In January I received an SMS with balance of R2968.36 On 30 January I settled this amount during February again I received an SMS saying that I owe them R352.86 which I didn't understand where it was coming from as I settled the amount. I kept receiving SMSs with the amount of R352.86 that is due at the of February. As I told them before that am not working and my arrangements was for R50 each and every month on the 4th of March I made a payment of R100 and on the 6th I made a payment of R52.86 my balance is suppose to R200 now you are telling me that I owe you R300 and something rand please stop milking money out me I am unemployed